-
The _____ leads from the cell body (neuron) and is covered with mylin sheath which faciliates the rate of transmission of an impulse.
axon
-
________ receive impulses at the synapse and lead toward the cell body (neuron).
Dendrites
-
The midbrain is beneath the ____________.
third ventricle
-
The spinal cord extends from the medulla oblongota to _______ at the conus medullaris.
L2-L3
-
What is the cauda equina?
"Horses tail": where spinal nerves extend past the end of the spinal cord.
-
The falx cerebri (part of the dura) divides?
cerebrum
-
The falx ceribelli (part of the dura) divides?
cerebellum
-
Tentouium cerebelli (part of the dura) divides?
cerebrum from the cerebellum
-
Middle "cobwebby layer" of the meninges?
arachnoid
-
Subarachnoid space is between the _______ and ______ and contains _______.
- arachnoid and pia mater
- CSF
-
What meningeal layer is highly vascular?
pia mater
-
CSF is secreated by the _________.
choroid plexus
-
Ventricle pathways: lateral ventricles to _________ to third ventricle to ________ to fourth ventricle to the _______ and ________.
- interventricular foramen (foramen of Monroe)
- Cerebral aquaduct (aquaduct of Sylvius)
- Median aperture (foraman of Magendie) and Lateral apertures (foramen of Luschka)
-
Blood supply to the brain: anteriorly? posteriorly?
- Anteriorly: bilateral internal carotid arteries
- Posteriorly: bilateral vertebral arteries
-
___________ communicates between the bilateral internal carotid arteries and the bilateral vertebral arteries.
- Circle of Willis
-
Circle of Willis is at about the level of the _______ in the brain.
sella turcica
-
About ____% of the population have a complete circle of willis.
50%
-
Venous blood from the brain is returned to the venous sinuses in the dura and ultimately drain into __________.
internal jugular veins.
-
The blood-brain barrier prevents passage of many substances into the brain. It is however, permeable to ____, ______, _____, ______ and general _______.
- H20
- CO2
- O2
- Alcohol
- anesthesia
-
What is inflammation of the meninges (pia and arachnoid layers)?
meningitis
-
-
Of bacterial and viral meningitis, which is more serious?
Bacterial
-
Severe headaches, stiff neck, high fever, intolerance to light, painful when moving eyes side to side are clinical signs of?
meningitis
-
The bacterial meningitis vaccine treats ___ different strands and protects for about ___ to ___ years.
-
An infected meninge may swell and close off the aquaduct between 3rd & 4th ventricle (aquaduct of Sylvius) which may lead to?
hydrocephalis
-
How is meningitis diagnosed?
lumbar punture
-
What is usually a viral infection of the brain tissue and meninges transmitted by herpes or "arborvirus"(arthropod borne)?
- Encephalitis
- Much more serious than meningitis
-
Pyogenic organisms from the ear, throat, lungs, and sinuses may cause a ______ in the brain.
abscess
-
Brain abscesses are best visualized with?
CT
-
Note: Posterior fossa tumor of cerebellum or 4th ventricle is more common in children and often a primary tumor.
-
Note: anterior cerebrum tumor is more common in adults and is usually a metasticis from another cancer.
-
Brain tumors are best visualized with?
MRI
-
Note:
Astrocytoma- benign, slow growing, infiltrative character and found in cerebrum, cerebellum, optic chiasm, pons.
-
Note:
Glioblastoma is a malignant converted grade 4 astrocytoma. Highly malignant and patients only live 6-12 months after diagnosis.
-
Most common form of adult primary brain tumor?
glioblastoma (patients only live 6-12 months after diagnosis, peel incidence 45-50yrs)
-
Note:
Medulloblastoma- posterior fossa most often in children (15-20% of all PED tumors) boys affect 2x more than girls, radiosensative.
-
Note:
Meningoma- benign tumor, often has calcifications, more common in females (30-50yrs) well encapsulated, and may compress teh brain. Well seen in CT and MR.
-
Note:
Acoustic Neuroma- slow growing benign tumor, arrises from cells in 8th cranial nerve. Originates in IAC and extends into the cerebellopontine cistern.
-
Slow growing benign tumor that arrises from the cells of the 8th cranial nerve?
acoustic neuroma
-
Note:
Pituitary adenoma- usually a benign tumor of anterior lobe of pituitary gland. Macroadenoma is over ____mm in size, and is also a _______ tumor. Tumor can compress teh pituitary gland causing hypopituitarism.
- 10mm
- non-functioning (pituitary functions normally)
-
What pathology may grow out and erode the sella turcica and compress the optic chiasm?
pituitary adenoma
-
Microadenoma of the pituitary gland (size _____) is a _____ tumor and causes _________ due to production of pituitary hormones.
- 1-10mm in size
- functioning
- hyperpituitarism
-
Pathology? Occurs primarily in males under 25yrs usually around it's calcifying time, and is midline of brain.
Pineal tumors
-
Linear skull fracture?
sharp lucent line that is often irregular, jagged and sometimes branches.
-
Diastatic skull fracture?
linear skull fracture that intersects a suture line and courses along it causing sutural separation.
-
Depressed skull fracture?
Often stellate (star shaped) with multiple fracture lines radiating outward from a central point
-
Hemotympanum?
blood coming from the ear, often a clinical sign of a basilar skull fracture.
-
Ecchymosis?
purple or black-and-blue area ................bruise
-
Epidural Hematomas (2% of all head injuries) are caused by acute _______ bleeding of the _____ _______ _____, most often over the __________ convexity.
- arterial
- medial meningeal artery
- parietotemporal
-
What type of hematoma appears as a biconvex (lens-shaped), peripheral, high density lesion?
epidural hematoma
-
Subdural hematomas (10-20% of all head injuries) are caused by _______ bleeding, most often caused by ruptured ______ between the dura mater and arachnoid.
-
An acute _______hematoma typically appears as a peripheral zone of increased density and has a crescentic shape.
subdural
-
What is an injury to the brain tissue that is caused by movement of the brain within the calvaria after blunt trauma to the skull?
cerebral contusion
-
What type of hemorrhage can produce bleeding into the ventricular system?
Subarachnoid hemorrhage
-
The ___________ artery is associated in 50% of traumatic fistulas.
internal carotid
-
The most common facial fracture is?
nasal bone fractures
-
What is caused by a direct blow to the front of the orbit that causes a rapid increase in intraorbital pressure?
blowout fracture
-
What method is the preferred screening study for a blowout fracture?
modified waters plain radiograph
-
What is a tripod fracture?
fractures of the zygomatic arch and the orbital floor or rim combined with separation of the zygomaticofrontal suture
-
Most common site of fracture of the mandible?
the angle
-
Le Fort fracture?
severe injury that involves bilateral and horizontal fractures of the maxillae (classified as I,II,III) resulting in a detached and unstable fragment.
-
Metastatic carcinoma of the brain most commonly arise from ______ (34%), and _________ (14%).
- lung cancer
- adenocarcinoma (breast)
-
Most sensative modality for detecting suspected tumors of the CNS?
MRI
-
What is a cobalt 60 gamma ray?
Gamma knife (201 beams converge in one spot)
-
Why isn't contrast given to patients suspected of a brain injury?
Because blood looks like contrast in CT
-
What is a "battle sign?"
ecchymosis over the mastoid processes
-
What are "raccoon eyes?"
bilateral orbital ecchymosis
-
If there are fluid levels visualized in sphenoid sinus and mastoid air cells, CSF and/or blood leaking out of ears, it may indicate?
a basilar fracture
-
What type of projection is required to view the depth of a depression fracture?
tangential
-
What modality ages blood really well?
MRI
-
What is caused by a shearing force to intraparenchymal arteries at the junction of gray and white matter?
intracerebral hematoma
-
Most common cause of subarachnoid hemorrhage?
reptured berry aneurysm: causes CVA, bleeds into ventricles
-
Most common type of cerebral vascular accident CVA?
Ischemic CVA (thrombus/embolus)
-
The onset of an embolus is often _____ not related to ______.
-
What is an AVM?
aretiovenus malformation- tangled web of arteries and veins
-
What is hemiplegia?
paralysis on one side of the body, usually dealing with strokes
-
What is hemiparesis?
weakness on one side of the body, usually dealing with strokes
-
What is dysarthria?
difficulty speaking, usually dealing with strokes
-
What is the purpose of radiographic evaluation in the acute stroke patient?
Not to confirm the diagnosis, but rather to exclude other processes that can stimulate the clinical finding.
-
Cerebral hemorrhage vs subarachnoid hemorrhage. Which has a poorer prognosis?
Subarachnoid
-
Symptoms: rapid hemiplegia, loss of consciousness, headache, stiff neck?
subarachnoid hemorrhage
-
1 in 3 experiencing a TIA will have a CVA within ____ years.
5
-
Degeneration of nerve tissue which causes mylin sheath in white matter of brain to degenerate. What is it?
- MS- multiple sclerosis
- May have a clinical sign of sudden blurred vision
-
Modality of choice for MS?
MRI
-
What type of seizure is mild where someone just kind of "spaces out?"
Petit Mal
-
What type of seizure is considered major with a loss of consciousness?
Grand Mal
-
Note: Alzheimer's Disease- Massive destruction of neurons, mental capacity deteriorates. States 1-5. Stage 3 requires assistance, stage 5 brain shuts down.
-
AD patients live _____-_______ years after diagnosis.
Alzheimer's Disease- 8-10 years
-
____% of people over 85 years old have Alzheimer's Disease.
25
-
AD is more common in males or females?
females
-
What disease is known as "shaking palsy?"
Parkinson's Disease
-
Neural transmitor dopamine is inadequately produced in this pathology?
Parkinson's Disease
-
Amyotrophic lateral sclerosis is also known as?
Lou Gehrig's Disease
-
Lou Gehrig's Disease: widespread selective atrophy with loss of motor nerve cells, leads to poralysis, death occures from respiratory weakness/aspiration pneumonia, and _________ is not affected.
intellect
-
Abnormal accumulation of CSF in the ventricles that causes increased intercranial pressure?
hydrocephalus
-
Most common cause of hydrocephalus?
spina bifida
-
Arnold-Chiari malformation?
cerebellar tonsils descend into upper cervical spinal canal and occlude foramina leading to subarachnoid space
-
Non-communicating hydrocephalus?
obstruction in ventricles proximal to medium and lateral apertures.
-
Communicating hydrocephalus?
Obstruction distal to medium and lateral apertures
-
Difference between non-communicating and communicating hydrocephalus?
non-communicating is proximal to medium and lateral apertures whereas communicating is distal.
-
US can be used to see the ventricular system in _____ only.
newborns- through the fontenel
-
Most common treatment for hydrocephalus?
VP shunt
-
What can cause osteomylitis or abscesses in the brain and meninges if left untreated?
sinusitis
-
Maxillary sinuses start out as _____ at birth.
slits
-
What sinus can you see by age 6?
ethmoid
-
What sinus is not well demonstrated until age 10?
Frontals
-
What sinus begin to develop at around age 2-3, and are fully developed in teens?
Sphenoid
-
What scan is perfomed to look for "brain death?"
radionuclide brain scan
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